Sensitive and reliable detection of glass transition of polymers. by fluorescent probes based on AIE luminogens

Transcription

1 Electronic Supplementary Material (ESI) for Polymer Chemistry. This journal is The Royal Society of Chemistry 2015 Supporting information Sensitive and reliable detection of glass transition of polymers by fluorescent probes based on AIE luminogens Suping Bao, a Qihua Wu, a Wei Qin, b Qiuling Yu, a Jing Wang, a Guodong Liang*,a and Ben Zhong Tang*,b a DSAP lab, PCFM lab, GDHPPC lab, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou , China. b HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen, China ; Department of Chemistry, Institute for Advanced Study, Division of Biomedical Engineering and Institute of Molecular Functional Materials, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Guangdong Innovative Research Team, SCUT-HKUST Joint Research Laboratory, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou , China. PS/TPE PS endo T g =89.5 C Temperature ( o C) Fig. S1 DSC curves of PS and PS/TPE (containing 1.0 wt% TPE) at heating rate of 1 ºC/min.

2 2.7 Å 2.3 Å Scheme S1 Geometric strucutre of TPE. Size of phenyl rings was estimated to be Å 2 using ChemBioDraw Ultra 12.0.

3 T g =110 C endo Temperature ( o C) Fig. S2 DSC curve of PMMA at heating rate of 1 ºC/min.

4 Temperatue dependence of elastic modulus of polymers. Fig. S3 Temperature dependence of elastic modulus of polymers taken from ref 1.

5 DSC traces for determination of T g. A B C D Fig. S4 DSC traces for determination of T g. Downloaded from internet at (A) (B) intechopen.com/source/html/16714/media/image13.jpg, (C) julkaisut/publications/2005/summary/p563/figure8.jpg, and (D) It is difficult to acurately determine T g from the DSC curves above (Fig. S4).

6 Measuring glass transition temperautre (T g ) by DSC. Fig. S5 Measuring glass transition temperautre (T g ) by DSC. Downloaded from internet at Glass transition takes place in a temperature range, as shown in Figue S8. Different operational definitions of T g are used, but all definitions are arbitary. For example, some researchers defined the point A on the curve (Figue S3) as T g, while others insisted on the point B as T g.

7 Synthesis. Synthesis of tetraphenylethene (TPE). A three-necked flask equipped with a magnetic stirrer was charged with zinc powder (7.85 g; 120 mmol) and 150 ml THF under N 2 atmosphere. The mixture was cooled to -5 to 0 C, and TiCl 4 (6.5 ml; 60 mmol) was slowly added by a syringe under 10 C. The mixture was restored to room temperature and stirred for 0.5 h, then reflux for 2.5 h. The mixture was cooled to -5 to 0 C, charged with pyridine (2.5 ml; 30 mmol) and stirred for 10 min. To the mixture was added 4.37 g benzophenone (24 mmol). The reaction mixture was refluxed for 24 h until the benzophenone was consumed (followed by TLC). The reaction was quenched with 20 ml of 10% K 2 C 3 aqueous solution, and filtrated to remove solid. The product was extracted with dicholomethane (3 50 ml). The organic layers were combined, washed with saturated brine solution and dried over anhydrous magnesium sulphate. The solvent was removed under reduced pressure to yield crude product. The crude product was purified by silica chromatography using hexane as eluent to give the desired products of tetraphenylethene (TPE). The compound emitted efficiently blue light under 365 nm radiation. 1 H NMR (400 MHz, CDCl 3 ), δ (TMS, ppm): (m, 12 H, Ar H), (m, 8H, Ar H). The 1 H NMR spectrum agreed with literature data. 2, 3 Zn, TiCl4 THF, reflux Scheme S2 Synthetic route for tetraphenylethene (TPE).

8 Synthesis of ethyl 4-(1,2,2-triphenylvinyl)benzoate (TPE-C2). 1-(4-Bromophenyl)-1,2,2-triphenylethene (1). The compound was synthesized according to the synthetic route shown in Scheme S3. Typical procedures were shown as follows. To a solution of diphenylmethane (2.02 g; 12 mmol) in dry tetrahydrofuran (50 ml) was added 6.25 ml of a 1.6 M solution of n-butyllithium in hexane (10 mmol) at -78 C under nitrogen. The resulting orange-red solution was stirred for 30 min at that temperature. To this solution was added 4- bromobenzophenone (2.35 g; 9 mmol). Afterwards, the reaction mixture was allowed to warm to room temperature and stirred for another 6 h. The reaction was quenched with the addition of an aqueous solution of ammonium chloride. The organic layer was then extracted with dichloromethane (3 50 ml). The organic layers were combined, washed with saturated brine solution and dried over anhydrous magnesium sulphate. After solvent evaporation, the resulting crude alcohol (containing excess diphenylmethane) was subjected to acid-catalyzed dehydration without further purification. The crude alcohol was dissolved in about 80 ml of toluene in a 100 ml Schlenk flask fitted with a Dean-Stark trap. A catalytic amount of p-toluenesulfonic acid (342 mg; 1.8 mmol) was added and the mixture was refluxed for 3 4 h. After the reaction mixture was cooled to room temperature, the toluene layer was washed with 10% aqueous NaHC 3 solution (2 25 ml) and dried over anhydrous magnesium sulfate. Evaporation of the solvent under reduced pressure afforded the crude tetraphenylethene derivative, which was further purified by silica gel column chromatography using hexane as eluent. Yield 92%. 1 H NMR (400 MHz, DMS-d 6 ), δ (TMS, ppm): (m, 17 H, Ar H), 7.32 (d, 2H, Ar H).

9 Li n-buli Br H THF, -78 o C THF, -78 o C Br PTSA toluene 1. n-buli, 2. C 2 ethanol DCC 1 Br TPE-C 2 H C 2 H TPE-C2 Scheme S3 Synthetic route for ethyl 4-(1,2,2-triphenylvinyl)benzoate (TPE-C2). 4-(1,2,2-Triphenylvinyl)benzoic acid (TPE-C 2 H). To a solution of 1 (1.6 g; 3.89 mmol) in 30 ml dry THF was added dropwise 2.9 ml (4.64 mmol) of n- butyllithium (1.6 M in n-hexane) at -78 C under stirring. The reaction mixture was stirred for 2 h to get a dark brown solution. To the obtained solution was then added dry ice pieces in small portions under nitrogen. The solution was allowed to warm to room temperature and stir for additional 12 h. The solvent was evaporated under reduced pressure. The crude product was purified on a silica-gel column using dichloromethane/methanol mixture (90/10 v/v) as eluent. Yield 85%. 1 H NMR (400 MHz, DMS-d 6 ), δ (TMS, ppm): (m, 17 H, Ar H), 7.66 (d, 2H, Ar H). 13 C NMR (400 MHz, CD 3 D), δ (TMS, ppm): 125.9, 126.8, and (Ar), and (C=C), (Ar), (C 2 H). HRMS (MALDF-TF): m/z (M +, calcd ). Ethyl 4-(1,2,2-triphenylvinyl)benzoate (TPE-C2) g TPE-C 2 H (1 mmol) was dissolved in 10 ml anhydrous DMF. To the solution was added 5 ml (2 mmol) ethanol and g (1 mmol) DCC at 0 C under nitrogen. The solution was stirred

10 for 2 h at 0 C, and was allowed to restore to room temperature. The solution was stirred at room temperature overnight. The solvent was removed under reduced pressure to yield crude product. The crude product was further purified by silica gel column chromatography using dichloromethane/methanol mixture (90/10 v/v) as eluent. Yield 82%. 1 H NMR (400 MHz, CDCl 3 ), δ (TMS, ppm): 1.36 (t, 3H,CH 3 ), 4.32 (dd, 2H, CH 2 CH 3 ), (m, 19H, Ar H), 7.93 (s, 2H, Ar H). HRMS (MALDF-TF): m/z [(M+1) +, calcd ]. Synthesis of 2-(tetraphenylethoxy)ethanol (TPE-C2H). To a solution of 3.94 g 4-hydroxybenzophenone (20 mmol) and 4.14 g potassium carbonate (30 mmol) in 50 ml acetone was added 2.84 ml 2-Bromoethanol (40 mmol). The mixture was refluxed under stirring for 24 h. After filtration and solvent evaporation, the crude product was purified by a silica gel column using chloroform as eluent to get compound 2. 1 H NMR (400 MHz, CDCl 3 ), δ (TMS, ppm): 4.0 (t, 2H, CH 2 H), 4.18 (t, 2H, CH 2 CH 2 ), 6.90 (d, 2H, Ar H), 7.48 (t, 2H, Ar H), 7.56 (t, 1H, Ar H), 7.74 (d, 2H, Ar H), 7.82 (d, 2H, Ar H). Br H H K 2 C 3, Aceton reflux 2 H H TPE-C2H Scheme S4 Synthetic route for 2-(tetraphenylethoxy)ethanol (TPE-C2H). A three-necked flask equipped with a magnetic stirrer was charged with zinc

11 powder (7.85 g; 120 mmol) and 150 ml THF under N 2 atmosphere. The mixture was cooled to -5 to 0 C, and TiCl 4 (6.5 ml; 60 mmol) was slowly added under 10 C. The mixture was restored to room temperature and stirred for 0.5 h, then reflux for 2.5 h. The mixture was cooled to -5 to 0 C, charged with pyridine (2.5 ml; 30 mmol) and stirred for 10 min. To the mixture were added 2.62 g benzophenone (14.4 mmol) and 2.90 g compound 2 (12 mmol). The reaction mixture was refluxed until the carbonyl compounds were consumed (followed by TLC). The reaction was quenched with 10% K 2 C 3 aqueous solution, and filtrated to remove insoluble solid. The product was extracted with dicholomethane (3 50 ml). The organic layers were combined, washed with saturated brine solution and dried over anhydrous magnesium sulphate. The solvent was removed under reduced pressure to yield crude product. The crude product was purified by silica chromatography using chloroform as eluent to give the desired products of 2-(tetraphenylethoxy)ethanol (TPE-C2H). The compound emitted efficiently blue light under 365 nm radiation. 1 H NMR (400 MHz, CDCl 3 ), δ (TMS, ppm): 3.92 (t, 2H, CH 2 H), 4.0 (t, 2H, CH 2 CH 2 ), 6.64 (d, 2H, Ar H), 6.94 (d, 2H, Ar H), (m, 6H, Ar H), (m, 9H, Ar H). The 1 H NMR spectrum agreed with literature data. 2, 3 References 1 C. A. Harper, Handbook of Plastics, Elastomers & Composites, The McGraw-Hill Companies, Inc., 2002.

12 2 G. D. Liang, L. T. Weng, J. W. Y. Lam, W. Qin and B. Tang, Acs Macro Lett., 2014, 3,. 3 G. D. Liang, J. W. Y. Lam, W. Qin, J. Li, N. Xie and B. Z. Tang, Chem. Commun., 2014, 50,.